The winner will be allowed to invite up to seven friends to have lunch with Buffett at the New York City steakhouse Smith & Wollenksy.

GLIDE operates on a budget of about $18 million. It serves more than 850,000 free meals a year, offers affordable housing, and operates a health clinic in a city with one of the highest levels of inequality in the country.

"The demand keeps growing," said GLIDE founding president Janice Mirikitani. "In this area, the cost of living is very high and a lot of people can't afford to pay for both food and rent," she said.

Buffett is one of the world's leading philanthropists. He started The Giving Pledge in 2010, an effort that has signed up more than 100 billionaires around the globe. They have pledged to donate half of their net worth during their lifetime, or at their death.